There is presently a real need for an instrument that could provide instantaneous, real-time conversionof thermal radiation to visible pictures. Such a device would have wide-ranging medical diagnostic applications, among them the detection of breast cancer and early diagnosis of incipient stroke, to name just the two. A unit such as this in mobile vans could provide simple and expeditious screening of vast numbers of people, rendering a useful and much needed service to the community at large. A double Fabry-Perot (FP) electrooptic, upconvertor is proposed that should allow real-time "viewing" of thermal images. The infrared and ruby laser radiations greatly enhance in amplitude by multiple reflections in the FP cavity interact wit each other to provide 6 to 8 orders of magnitude improvement in upconversion efficiency compared to single-pass schemes. Bright visible pictures bearing the intensity pattern of the weak thermal image are shown feasible. In order to improve the contrast of the picture, the average emission could be blanked out to the extent necessary by Fourier optical techniques.